just create new peds and put them into the car.
to put the ped into the car you can use:
Ped ped = new Ped();
ped.IsPersistent = true;
ped.BlockPermanentEvents = true;
ped.Tasks.EnterVehicle(vehicle, 0, EnterVehicleFlags.WarpIn);
the 2nd parameter is the seat pos (-1=driver, 0= front passenger, 1 or 2=rear passengers)

there's no LSPDFR crash detected.
it's most probably GTA V crash which might be caused by corrupted mods (texture or models) or not enough memory error (bad gameconfig.xml)
if you have mods, please try to disable them and only run vanilla GTA V + RPH + LSPDFR. Let's see how it's going.

there's no LSPDFR crash detected.
it's most probably GTA V crash which might be caused by corrupted mods (texture or models) or not enough memory error (bad gameconfig.xml)
if you have mods, please try to disable them and only run vanilla GTA V + RPH + LSPDFR. Let's see how it's going.

not only CPU. RAM speed and GPU will also affect performance.
as i stated on another thread. if you want to play LSPDFR in a particular FPS. First, you need to be able to run vanilla GTA V at twice of your target FPS
for example, if you want to run LSPDFR in 60FPS, your vanilla GTA V should run at at least 120FPS
why LSPDFR is dragging down the FPS? basically it is also related to how RPH works.
RPH is battling the GTA V anti-modding protection and it has its own algorithm to bypass it on every tick of the rendering process.
the price for that additional overhead is the FPS drop.
source: https://kotaku.com/gtav-on-pc-gets-slower-mod-protection-blamed-1717419626